• Install:

  npm install -g @anthropic-ai/claude-code

• Auth: run

  claude

  once to log in (browser OAuth for Pro/Max, or set

  ANTHROPIC_API_KEY

  )
• Console auth:

  claude auth login --console

  for API key billing
• SSO auth:

  claude auth login --sso

  for Enterprise
• Check status:

  claude auth status

  (JSON) or

  claude auth status --text

  (human-readable)
• Health check:

  claude doctor

  — checks auto-updater and installation health
• Version check:

  claude --version

  (requires v2.x+)
• Update:

  claude update

  or

  claude upgrade

terminal(command="claude -p 'Add error handling to all API calls in src/' --allowedTools 'Read,Edit' --max-turns 10", workdir="/path/to/project", timeout=120)

• One-shot coding tasks (fix a bug, add a feature, refactor)
• CI/CD automation and scripting
• Structured data extraction with

  --json-schema

• Piped input processing (

  cat file | claude -p "analyze this"

  )
• Any task where you don't need multi-turn conversation

1. CLI flags — override everything
2. Local project:

   .claude/settings.local.json

   (personal, gitignored)
3. Project:

   .claude/settings.json

   (shared, git-tracked)
4. User:

   ~/.claude/settings.json

   (global)

1. Global:

   ~/.claude/CLAUDE.md

   — applies to all projects
2. Project:

   ./CLAUDE.md

   — project-specific context (git-tracked)
3. Local:

   .claude/CLAUDE.local.md

   — personal project overrides (gitignored)

#

# Always use 2-space indentation

1. Run all tests
2. Build the Docker image
3. Push to registry
4. Update the $ARGUMENTS environment (default: staging)

Usage: `/deploy production` — `$ARGUMENTS` is replaced with the user's input.

1. Use Alembic for migration generation
2. Always create a rollback function
3. Test migrations against a local database copy

undefined

• FastAPI backend with SQLAlchemy ORM
• PostgreSQL database, Redis cache
• pytest for testing with 90% coverage target

• make test

  — run full test suite

• make lint

  — ruff + mypy

• make dev

  — start dev server on :8000

• Type hints on all public functions
• Docstrings in Google style
• 2-space indentation for YAML, 4-space for Python
• No wildcard imports

**Be specific.** Instead of "Write good code", use "Use 2-space indentation for JS" or "Name test files with `.test.ts` suffix." Specific instructions save correction cycles.

• Project rules:

  .claude/rules/*.md

  — team-shared, git-tracked
• User rules:

  ~/.claude/rules/*.md

  — personal, global

.md

~/.claude/projects/<project>/memory/

• Limit: 25KB or 200 lines per project
• This is separate from CLAUDE.md — it's Claude's own notes about the project, accumulated across sessions

1. .claude/agents/

   — project-level, team-shared

2. --agents

   CLI flag — session-specific, dynamic

3. ~/.claude/agents/

   — user-level, personal

name: security-reviewer description: Security-focused code review model: opus tools: [Read, Bash]

• Injection vulnerabilities (SQL, XSS, command injection)
• Authentication/authorization flaws
• Secrets in code
• Unsafe deserialization

Invoke via: `@security-reviewer review the auth module`

• Tool descriptions: 2KB cap per server for tool descriptions and server instructions
• Result size: Default capped; use

  maxResultSizeChars

  annotation to allow up to 500K characters for large outputs
• Output tokens:

  export MAX_MCP_OUTPUT_TOKENS=50000

  — cap output from MCP servers to prevent context flooding
• Transports:

  stdio

  (local process),

  http

  (remote),

  sse

  (server-sent events)

/context

• < 70% — Normal operation, full precision
• 70-85% — Precision starts dropping, consider

  /compact

• > 85% — Hallucination risk spikes significantly, use

  /compact

  or

  /clear

1. Use

   --max-turns

   in print mode to prevent runaway loops. Start with 5-10 for most tasks.
2. Use

   --max-budget-usd

   for cost caps. Note: minimum ~$0.05 for system prompt cache creation.
3. Use

   --effort low

   for simple tasks (faster, cheaper).

   high

   or

   max

   for complex reasoning.
4. Use

   --bare

   for CI/scripting to skip plugin/hook discovery overhead.
5. Use

   --allowedTools

   to restrict to only what's needed (e.g.,

   Read

   only for reviews).
6. Use

   /compact

   in interactive sessions when context gets large.
7. Pipe input instead of having Claude read files when you just need analysis of known content.
8. Use

   --model haiku

   for simple tasks (cheaper) and

   --model opus

   for complex multi-step work.
9. Use

   --fallback-model haiku

   in print mode to gracefully handle model overload.
10. Start new sessions for distinct tasks — sessions last 5 hours; fresh context is more efficient.
11. Use

    --no-session-persistence

    in CI to avoid accumulating saved sessions on disk.

1. Interactive mode REQUIRES tmux — Claude Code is a full TUI app. Using

   pty=true

   alone in Hermes terminal works but tmux gives you

   capture-pane

   for monitoring and

   send-keys

   for input, which is essential for orchestration.

2. --dangerously-skip-permissions

   dialog defaults to "No, exit" — you must send Down then Enter to accept. Print mode (

   -p

   ) skips this entirely.

3. --max-budget-usd

   minimum is ~$0.05 — system prompt cache creation alone costs this much. Setting lower will error immediately.

4. --max-turns

   is print-mode only — ignored in interactive sessions.
5. Claude may use

   python

   instead of

   python3

   — on systems without a

   python

   symlink, Claude's bash commands will fail on first try but it self-corrects.
6. Session resumption requires same directory —

   --continue

   finds the most recent session for the current working directory.

7. --json-schema

   needs enough

   --max-turns

   — Claude must read files before producing structured output, which takes multiple turns.
8. Trust dialog only appears once per directory — first-time only, then cached.
9. Background tmux sessions persist — always clean up with

   tmux kill-session -t <name>

   when done.
10. Slash commands (like

    /commit

    ) only work in interactive mode — in

    -p

    mode, describe the task in natural language instead.

11. --bare

    skips OAuth — requires

    ANTHROPIC_API_KEY

    env var or an

    apiKeyHelper

    in settings.
12. Context degradation is real — AI output quality measurably degrades above 70% context window usage. Monitor with

    /context

    and proactively

    /compact

    .

1. Prefer print mode (

   -p

   ) for single tasks — cleaner, no dialog handling, structured output
2. Use tmux for multi-turn interactive work — the only reliable way to orchestrate the TUI
3. Always set

   workdir

   — keep Claude focused on the right project directory
4. Set

   --max-turns

   in print mode — prevents infinite loops and runaway costs
5. Monitor tmux sessions — use

   tmux capture-pane -t <session> -p -S -50

   to check progress
6. Look for the

   ❯

   prompt — indicates Claude is waiting for input (done or asking a question)
7. Clean up tmux sessions — kill them when done to avoid resource leaks
8. Report results to user — after completion, summarize what Claude did and what changed
9. Don't kill slow sessions — Claude may be doing multi-step work; check progress instead
10. Use

    --allowedTools

    — restrict capabilities to what the task actually needs